Abstract：In-situ stress and groundwater have important influences upon the design and construction of the lining for deep and long tunnels. The mechanical properties of segment linings for deep and long tunnels of west route of South-to-North Water Transfer Project are analyzed by using numerical simulation method. The influence of surrounding rock deformation and water pressure on the segment linings is studied. The preliminary results show that the segment linings can be used in approximate 90% segment of the tunnel as the surrounding rock has a good stability and the deformation has less influence upon segment linings. The external water pressure is very high around the tunnel，which is the main factor affecting the design of tunnel lining. The measures of high-pressure concrete grouting should be applied to decrease the external water pressure. The results can provide a basis for the design of linings in the first phase of the west route of South-to-North Water Transfer Project.
